KLUEDO RSS FeedKLUEDO Dokumente/documentshttps://kluedo.ub.uni-kl.de/index/index/
Sun, 15 Apr 2007 00:41:54 +0200Sun, 15 Apr 2007 00:41:54 +0200Mapping of formal Network Quality-of-Service Requirementshttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/1853
The provision of network Quality-of-Service (network QoS) in wireless (ad-hoc) networks is a major challenge in the development of future communication systems. Before designing and implementing these systems, the network QoS requirements are to be specified. Since QoS functionalities are integrated across layers and hence QoS specifications exist on different system layers, a QoS mapping technique is needed to translate the specifications into each other. In this paper, we formalize the relationship between layers. Based on a comprehensive and holistic formalization of network QoS requirements, we define two kinds of QoS mappings. QoS domain mappings associate QoS domains of two abstraction levels. QoS scalability mappings associate utility and cost functions of two abstraction levels. We illustrate our approach by examples from the case study Wireless Video Transmission.Webel Christian; Gotzhein Reinhard; Schneider Danielreporthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/1853Sun, 15 Apr 2007 00:41:54 +0200Formalization of Network Quality-of-Service Requirementshttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/1852
The provision of network Quality-of-Service (network QoS) in wireless (ad-hoc) networks is a major challenge in the development of future communication systems. Before designing and implementing these systems, the network QoS requirements are to be specified. Existing approaches to the specification of network QoS requirements are mainly focused on specific domains or individual system layers. In this paper, we present a holistic, comprehensive formalization of network QoS requirements, across layers. QoS requirements are specified on each layer by defining QoS domain, consisting of QoS performance, reliability, and guarantee, and QoS scalability, with utility and cost functions. Furthermore, we derive preorders on multi-dimensional QoS domains, and present criteria to reduce these domains, leading to a manageable subset of QoS values that is sufficient for system design and implementation. We illustrate our approach by examples from the case study Wireless Video Transmission.Webel Christian; Gotzhein Reinhard; Schneider Danielreporthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/1852Sun, 15 Apr 2007 00:41:42 +0200SDL Profiles - Definition and Formal Extractionhttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/1807
Over a period of 30 years, ITU-T’s Specification and Description Language (SDL) has matured to a sophisticated formal modelling language for distributed systems and communication protocols. The language definition of SDL-2000, the latest version of SDL, is complex and difficult to maintain. Full tool support for SDL is costly to implement. Therefore, only subsets of SDL are currently supported by tools. These SDL subsets - called SDL profiles - already cover a wide range of systems, and are often suffcient in practice. In this report, we present our approach for extracting the formal semantics for SDL profiles from the complete SDL semantics. We then formalise the approach, present our SDL-profile tool, and report on our experiences.Rüdiger Grammes; Reinhard Gotzheinreporthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/1807Tue, 21 Nov 2006 12:53:38 +0100Eine Estelle-Erweiterung zur Steigerung der Nebenlaeufigkeithttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/268
Jan Bredereke; Reinhard Gotzheinarticlehttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/268Mon, 03 Apr 2000 00:00:00 +0200Increasing the Concurrency in Estellehttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/286
Jan Bredereke; Reinhard Gotzheinarticlehttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/286Mon, 03 Apr 2000 00:00:00 +0200Specification, Detection and Resolution of IN Feature Interactions with Estellehttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/297
Jan Bredereke; Reinhard Gotzheinarticlehttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/297Mon, 03 Apr 2000 00:00:00 +0200A Case Study on Specifikation,Detection and Resolution of IN Feature Interactions with Estellehttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/74
We present an approach for the treatment of Feature Interactions in Intelligent Networks. The approach is based on the formal description technique Estelle and consists of three steps. For the first step, a specification style supporting the integration of additional features into a basic service is introduced . As a result, feature integration is achieved by adding specification text, i.e . on a purely syntactical level. The second step is the detection of feature interactions resulting from the integration of additional features. A formal criterion is given that can be used for the automatic detection of a particular class of feature interactions. In the third step, previously detected feature interactions are resolved. An algorithm has been devised that allows the automatical incorporation of high-level design decisions into the formal specification. The presented approach is applied to the Basic Call Service and several supplementary interacting features.Jan Bredereke; Reinhard Gotzheinpreprinthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/74Mon, 03 Apr 2000 00:00:00 +0200Improving the Efficiency of Automated Protocol Implementation Using Estellehttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/149
Correctness and runtime efficiency are essential properties of software ingeneral and of high-speed protocols in particular. Establishing correctnessrequires the use of FDTs during protocol design, and to prove the protocolcode correct with respect to its formal specification. Another approach toboost confidence in the correctness of the implementation is to generateprotocol code automatically from the specification. However, the runtimeefficiency of this code is often insufficient. This has turned out to be amajor obstacle to the use of FDTs in practice.One of the FDTs currently applied to communication protocols is Es-telle. We show how runtime efficiency can be significantly improved byseveral measures carried out during the design, implementation and run-time of a protocol. Recent results of improvements in the efficiency ofEstelle-based protocol implementations are extended and interpreted.Reinhard Gotzhein; Jan Bredereke; W. Effelsberg; S. Fischer; T. Held; H. Königpreprinthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/149Mon, 03 Apr 2000 00:00:00 +0200Design of a Formal Estelle Semantics for Verificationhttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/305
AbstractOne main purpose for the use of formal description techniques (FDTs) is formal reasoningand verification. This requires a formal calculus and a suitable formal semantics of theFDT. In this paper, we discuss the basic verification requirements for Estelle, and howthey can be supported by existing calculi. This leads us to the redefinition of the stanADdard Estelle semantics using Lamport's temporal logic of actions and Dijkstra's predicatetransformers.Jan Bredereke; Reinhard Gotzhein; F. H. Vogtpreprinthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/305Mon, 03 Apr 2000 00:00:00 +0200A Generic Approach to the Formal Specification of Requirementshttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/317
Christian Peper; Reinhard Gotzhein; Martin Kronenburgpreprinthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/317Mon, 03 Apr 2000 00:00:00 +0200Generic Layout of Communication Subsystems - A Case Studyhttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/435
The purpose of this expose is to explain the generic design of a customized communication subsystem. The expose addresses both functional and non-functional aspects. Starting point is a real-time requirement from the application area building automation. We show how this application requirement and some background information about the application area lead to a system architecture, a communication service, a protocol architecture and to the selection, adaptation, and composition of protocol functionalities. The reader will probably be surprised how much effort is necessary in order to implement the innocuous, innocent, inconspicuous looking application requirement. Formal description techniques (FDTs) will be used in all design phases.Reinhard Gotzhein; Birgit Geppert; Christian Peper; Frank Roesslerpreprinthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/435Mon, 03 Apr 2000 00:00:00 +0200A Clock-independent Model for Real-Timehttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/437
A new approach for modelling time that does not rely on the concept of a clock is proposed. In order to establish a notion of time, system behaviour is represented as a joint progression of multiple threads of control, which satisfies a certain set of axioms. We show that the clock-independent time model is related to the well-known concept of a global clock and argue that both approaches establish the same notion of time.Frank Roessler; Birgit Geppert; Reinhard Gotzheinpreprinthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/437Mon, 03 Apr 2000 00:00:00 +0200Specifying and Reasoning about Generic Real-Time Requirements - A Case Studyhttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/439
A non-trivial real-time requirement obeying a pattern that can be foundin various instantiations in the application domain building automation, and which is therefore called generic, is investigated in detail. Starting point is a description of a real-time problem in natural language augmented by a diagram, in a style often found in requirements documents. Step by step, this description is made more precise and finally transformed into a surprisingly concise formal specification, written in real-time temporal logic with customized operators. Wereason why this formal specification precisely captures the original description- as far as this is feasible due to the lack of precision of natural language.Reinhard Gotzhein; Martin Kronenburg; Christian Peperpreprinthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/439Mon, 03 Apr 2000 00:00:00 +0200A Tailored Real Time Temporal Logic for Specifying Requirements of Building Automation Systemshttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/440
A tailored real time temporal logic for specifying requirements of building automation systems is introduced and analyzed. The logic features several new real time operators, which are chosen with regard to the application area. The new operators improve the conciseness and readability of requirements as compared to a general-purpose real time temporal logic. In addition, some of the operators also enhance the expressiveness of the logic. A number of properties of the new operators are presented and proven.Martin Kronenburg; Reinhard Gotzhein; Christian Peperpreprinthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/440Mon, 03 Apr 2000 00:00:00 +0200Formal Specifications of Real-Time Requirements for Building Automation Systemshttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/441
A generic approach to the formal specification of system requirements is presented. It is based on a pool of requirement patterns, which are related to design patterns well-known in object-oriented software development. The application of such patterns enhances the reusability and genericity as well as the intelligibility of the formal requirement specification. The approach is instantiated by a tailored real-time temporal logic and by selecting building automation systems as application domain. With respect to this domain, the pattern discovery and reuse tasks are explained and illustrated, and a set of typical requirement patterns is presented. Finally, the results of a case study where the approach has been applied are summarized.Martin Kronenburg; Reinhard Gotzhein; Christian Peperpreprinthttps://kluedo.ub.uni-kl.de/frontdoor/index/index/docId/441Mon, 03 Apr 2000 00:00:00 +0200